Aqueous additive systems, methods and polymeric particles

ABSTRACT

Aqueous application systems for applying additives to polymeric particles, methods of preparing aqueous emulsions which include at least one processing, stabilizing or other functional polymer additive and an emulsifiable wax. Also disclosed are methods of applying additives to polymeric particles and to polymeric particles treated by such methods.

This application is a continuation-in-part of application Ser. No.240,903 filed Sep. 6, 1988 now U.S. Pat. No. 5,007,961, which is acontinuation-in-part of application Ser. No. 197,946 filed May 24, 1988now U.S. Pat. No. 4,975,120; which is a continuation-in-part ofapplication Ser. No. 827,042 filed Feb. 7, 1986 now U.S. Pat. No.4,898,616, which is a continuation-in-part of application Ser. No.701,888 filed Feb. 15, 1985 now abandoned, all of which are herebyincorporated by reference in their entirety.

TECHNICAL FIELD

This invention relates to aqueous application systems for applyingadditives to polymeric particles and methods of preparing aqueousemulsions which include additives having a high melting point, additiveswhich have a low melting point and an emulsifiable wax. The inventionfurther relates to methods of applying additives to polymeric particlesand to polymeric particles treated by such methods.

BACKGROUND OF THE INVENTION

Known methods of introducing additives to polymeric particles includedry blending the materials, melting, and compounding the melted blendwith extruders and pelletizing or powdering to the desired physicalform. The additives employed to treat polymeric particles includeantioxidants, processing aids, slip agents, antiblocking agents,antistatic agents, lubricants, UV stabilizers, coupling agents andcolorants.

Another method of introducing additives to polymeric particles is tocontact such particles with additive at the extruder hopper during enduse processing. Additives such as colorants, slip agents, processingaids, blowing agents, and others are introduced to virgin polymericparticles at this stage usually in concentrate form. In many instances,difficulty is encountered in metering the exact amounts of additiveconcentrate necessary to do a specific job. This is especially true foradditives such as processing aids and external lubricants which are usedat very low levels and usually cannot be added in a concentrate form.

Some polymers are presently being manufactured with technology that doesnot lend itself to such techniques as melt compounding and pelletizing.Many polymers such as high density polyethylene, linear low densitypolyethylene, and polypropylene emerge from the polymerization reactorin a dry granular form, i.e., in a form similar to that of a fluidizedbed system. Presently, additives for these polymers must be introducedby melting, compounding, and then pelletizing. This extra step increasesthe cost of such polymer manufacturing operations and can adverselyeffect the properties of such polymers.

SUMMARY OF THE INVENTION

In accordance with the present invention, a wide range of additives,such as antioxidants or thermal stabilizers, colorants or the like canbe incorporated into the aqueous emulsified or dispersed systems of thisinvention. The aqueous emulsions or dispersions can be used to coat thepolymeric particles before normal drying or degasing operationsemploying a variety of techniques such as, for example employing aspray, wipe, or dip system. Such aqueous systems may be formulated totreat polymeric particles which can then be formed into materials madefrom such particles. The resulting materials may be used in applicationssuch as film or packaging for food, medicine and the like. Also, suchaqueous systems may contain lubricants, mold release agents, antistaticagents and the like.

Polymers which emerge from the polymerization reactor in particle formwould substantially benefit from the application of such aqueousemulsions containing antioxidants and other additives by means of suchan aqueous treatment. This means of introducing additives wouldeliminate melt compounding, lower production energy requirements, andminimize heat history on the polymer particles.

DETAILED DESCRIPTION OF THE INVENTION

The present invention concerns aqueous application systems for applyinga variety of additives to polymeric particles, the resulting systembeing characterized by freedom from in situ formation of color producingcomplexes. The invention application systems comprise:

a) an emulsified wax,

b) in the range of 0.025 up to 60 parts by weight of surfactant per partof emulsified wax,

c) in the range of 0.0005 up to 2 parts by weight of a base with a pH inthe range of greater than 7 to equal to or less than about 12,

d) in the range of 0.05 up to 160 parts by weight of at least oneprocessing, stabilizing or other functional polymer additive, and

e) at least enough water to render the resulting combination fluid.

Preferred application systems of the present invention comprise:

a) emulsified wax,

b) in the range of about 0.025 up to 4.2 parts of surfactant,

c) in the range of about 0.0005 up to 0.2 parts base,

d) in the range of about 0.05 up to 60 parts additive(s), and

e) sufficient water to render the resulting combination free-flowing.

In accordance with a particular preferred embodiment of the presentinvention, there are provided relatively concentrated applicationsystems which comprise in the range of about 2 up to about 30 percent byweight of surfactant, in the range of about 5 up to about 20 percent byweight of emulsified wax, in the range of about 0.2 to about 1.0 percentby weight of base, about 30 to about 80 percent by weight of additive,and at least 5, but less than about 40 percent by weight of water.

In accordance with another particularly preferred embodiment of thepresent invention, there are provided relatively high water contentapplication systems which comprise in the range of about 0.1 up to 5percent by weight of surfactant, in the range of about 0.5 up to 10percent by weight of emulsified wax, in the range of about 0.02 up to0.5 percent by weight of base, about 2 up to 23.5 percent by weight ofadditive, and greater than at least 60 up to about 97 percent by weightof water.

The base employed in the practice of the present invention may beselected from alkali metal salts of weak acids, e.g., sodiumtetraborate, sodium carbonate, sodium bicarbonate, potassium hydroxide;alkaline earth salts of weak acids, e.g., calcium carbonate or magnesiumcarbonate, and the like.

The additives employed in the practice of the present invention may beselected from antioxidants, e.g , tetrakis[methylene3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)-propionate]methane, octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate,1,3,5-trimethyl-2,4,6-tris-(3,5-di-tert-butyl)-4-(hydroxybenzyl)benzene,bis(2,4-di-t-butyl-phenyl) pentaerythritol diphosphite, tris(monononylphenyl)phosphite, 4,4'-butylidene-bis(5-methyl-2-t-butyl)phenol,tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, tris-nonylphenylphosphite; distearyl pentaerythritol diphosphite;tetrakis-(2,4-di-t-butylphenyl)-4,4'-biphenylylene-diphosphonite;tris-(2,3-di-t-butylphenyl) phosphite; butylated hydroxy toluene;dicetyl thiodipropionate; dimyristyl thiodipropionate; poly(1,4-cyclohexylenedimethylene-3,3'-thiodipropionate (partiallyterminated with stearyl alcohol); and the like; coupling agents, e.g.,silanes; titanates; chromium complexes; low molecular weight polyolefins(with carboxylic moieties); high molecular weight polyolefins andacrylates (with carboxylic moieties); chlorinated paraffins; and thelike; antistatic agents, e.g., glycerol monostearates; ethoxylatedamines; polyethylene glycol; quaternary ammonium compounds (salts); andthe like; nucleating agents, e.g., sodium benzoate; diphenyl phosphinicacid (including magnesium, sodium, calcium, aluminum salts); phenylphosphinic acid (including salts); phenyl phosphorous acid (includingsalts); and the like; metal deactivators, e.g., oxalyl bis(benzylidenehydrazide); 2,2'-oxamido bis-(ethyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate; and the like; lubricants/slip agents/antiblocking agents,e.g., diatomaceous silica (earth); talc; clay; metallic stearates; alkylbis-stearamids; glycerol monostearates; polyethylene glycol; erucamid;oleamid, and the like; UV inhibitors, e.g.,2-hydroxy-4-octoxybenzophenone; 2-hydroxy-4-isooctoxybenzophenone;4-hydroxy-4-n-dodecyloxybenzophenone;2-(3-di-t-butyl-2-hydroxy-5-methylphenyl5-chlorobenzotriazole;2-(2-hydroxy-3,5-di-tamylphenyl) benzotriazole; p-t-butylphenylsalicyllate; 2,4-di-t-butylphenyl-3,5-di-t-buty14-hydroxybenzoate;nickel bis-ortho-ethyl(3,5-dit-butyl-4-hydroxybenzyl) phosphonate;2,2',6,6'tetramethyl-4-piperidinyl sebacate, and the like; flameretardants, e.g., decabromodiphenyl oxide; dodecachlorodimethanedibenzocyclooctane; ethylene bis-dibromo norbornane dicarboximide;ethylene bis-tetrabromophthalimide; antimony trioxide, and the like;biocides, e.g., methyl paraben, ethyl paraben, propyl paraben,halogenated alkyl organic compounds, transition metal carbamate salts,and the like; as well as mixtures of any two or more of the abovementioned classes of compounds, or mixtures of two or more compoundsfrom within a given class of compound.

The aqueous application systems of the present invention can be preparedby first agitating a combination comprising in the range of about 5 upto 35 wt. % emulsifiable wax, in the range of about 0.2 up to 1.0 wt. %base, in the range of about 2 up to 30 wt. % surfactant and in the rangeof 20 up to 80 wt. % water in a pressure vessel at a temperaturesufficient to melt all solids and at a pressure sufficient to preventboiling of the vessel contents for a time in the range of about 0.1 upto 6 hours. Once all solids have been melted and the mixture thoroughlycombined, the vessel contents are rapidly cooled to room temperature.

The resulting emulsion (20-70 wt. %), the additive(s) to be incorporatedinto the invention application system (30-80 wt. %), optionally,additional water (0-35 wt. %) and, optionally, antifoam agent (0-1%) areall charged to a ball mill, sand mill, hammer mill, or the like with theresulting combination then being subjected to milling for a time in therange of about 2 up to 24 hours. The emulsion/dispersion obtained fromthis milling procedure is then ready for application to polymerparticles as described hereinafter in greater detail.

Prior to use for application to polymer particles, theemulsion/dispersion prepared as described above can optionally bediluted with additional quantities of water, if desired. Such dilutionmay be carried out, for example, to improve the ease of application ofthe emulsion/dispersion to polymer particles, and to make it easy tovary the quantity of additive applied to the polymer particles.

The invention also includes methods of applying a wide range ofadditives to polymeric particles, the method comprising contacting theparticles with emulsions/suspensions disclosed herein and subsequentlydrying the particles to leave the solids adhering to the particles.

The invention further includes polymeric particles prepared by themethods disclosed in this specification.

Aqueous emulsions or dispersions containing potassium hydroxide orsodium hydroxide, and additives such as processing aids, stabilizers orother functional additives for polymeric particles, may cause theformation of color complexes when certain additives are present, such asn-octadecyl 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionate, ahindered phenolic primary antioxidant. This color complex formationimparts undesirable color to the polymeric particles to which theaqueous emulsions or dispersions are applied.

However, when such aqueous emulsions or dispersions contain sodiumtetraborate, sodium carbonate, calcium carbonate, or magnesiumcarbonate, or a similar base component in the pH range of greater thanabout 7 to less than about 12, color complex formation is not observed.Such emulsions or dispersions containing a base such as sodiumtetraborate can also contain additives such as stabilizer, for example,n-octadecyl 3-(3',5'-ditert-butyl-4'-hydroxyphenyl) propionate, withoutimparting color to the polymeric particles to which the aqueousemulsions or dispersions containing the additives are applied. Theaddition level of sodium tetraborate or a similar weak base to theaqueous emulsions or dispersions may vary from 0.2-1.0% by weight.

The aqueous emulsions or dispersions of this invention contain inaddition to water, an emulsifiable wax, and one or more of a variety ofthe desired additives, stabilizers, colorants and the like.

The emulsifiable wax employed in the practice of the present inventionmay be any wax which can be readily emulsified, for example,emulsifiable polyolefin waxes such as oxidized polyolefin waxes ormodified polyolefin waxes. Preferred oxidized polyolefin waxes includewaxes having a density in the range of about 0.92-0.96, melt viscositiesin the range of about 50-4,000 cp at 125° C. and an acid number in therange of about 12-55. Exemplary waxes include an oxidized polyethylenewax having a density of 0.939, a melt viscosity of 250 cp at 125° C. andan acid number of 16; an oxidized polyethylene wax having a density of0.942, a melt viscosity of 900 cp at 125° C. and an acid number of 15;an oxidized polyethylene wax having a density of 0.955, a melt viscosityof 250 cp at 125° C. and an acid number of 16; and a maleatedpolypropylene wax having a density of 0.934, a melt viscosity of 400 cpat 190° C. and an acid number of 47.

The aqueous emulsions/dispersions prepared in accordance with thepresent invention may contain a variety of emulsifiable waxes, e.g., anemulsifiable polyethylene wax having a density of 0.939, a meltviscosity of 250 cp at 125° C. and an acid number of 16. Such emulsionsmay also contain surfactants and emulsifiers such as commerciallyavailable Tergitol 15-S-15 (an ethoxylated linear alcohol having ahydrophylic-lipophilic balance of 15.4, as determined according toGriffin, W. C., Office. Dig. Federation Paint Varnish Prod. Blubs, 28,446 (1956)), and anti-foam agents such as SWS-211 (a mixture of foodgrade emulsifiers, 10% by wt. silicone compounds, and water). Suchemulsions may also contain potassium hydroxide, sodium tetraborate,sodium carbonate, sodium bicarbonate, calcium carbonate or magnesiumcarbonate, morpholine, 2-amino-2-methylpropanol, tall oil fatty acid,ethylene glycol and ethoxylated stearyl alcohol (commercially availableas Industrol A99), and the like.

Additives employed in the practice of the present invention include suchmaterials as antioxidants, including, for example, hindered phenols,thioesters, organophosphites, and hindered amines, which may readily bedispersed or emulsified in the aqueous emulsion system. Additionaladditives contemplated by the present invention include coupling agents,antistatic agents, nucleating agents, metal deactivators, lubricants,slip agents, antiblocking agents, uv inhibitors, flame retardants andthe like.

Examples of suitable polymer particles that can be benefited from thepresent invention include particles made from polyolefins includingpolypropylenes such as crystalline polypropylene, and polyethylenes suchas low density polyethylene, high density polyethylene and linear lowdensity polyethylene; olefin copolymers including ethylene copolymersand propylene copolymers such as crystalline propylene-ethylenecopolymers and rubbers such as ethylene-propylene rubber and the like;polystyrene; polyesters and copolyesters such as polyethyleneterephthalate, polybutylene terephthalate and the like; polyamides;polyimides; polyacetals; polycarbonates; polyvinyl chloride polymers andcopolymers; polyaromatic sulfones; polyaromatic ketones;chlorosulfonated polyethylene; ethylenepropylene terpolymers; butylrubbers; butadiene-styrene rubbers; silicone acrylonitrile rubbers;polyvinylidene chloride; acrylonitrile-butadiene-styrene;polycaprolactone; poly(ethylene oxide); chlorinated polyethylene;polymethyl methacrylate; and the like.

Some preferred polymeric particles that can benefit from the presentinvention include particles made from polyolefins such as crystallinepolypropylene, low density polyethylene, high density polyethylene, andlinear low density polyethylene; propylene-ethylene copolymers;polyvinyl chloride polymers and copolymers; polystyrene; polyimides;polyamides; and acrylonitrilebutadiene-styrene. The most preferredparticles are made from ethylene and propylene polymers and copolymers,and acrylonitrile-butadiene-styrene.

The present invention provides polymeric particles which are stabilizedin a unique and efficient manner and which are free from undesirablecolor.

The invention will be further illustrated by the following examplesalthough it will be understood that these examples are included merelyfor purposes of illustration and are not intended to limit the scope ofthe invention.

EXAMPLE 1

The emulsions used in the following examples are prepared as follows:The components of the emulsion including an emulsifiable wax, a base, asurfactant, and an additive and sufficient water for a solids content ofabout 60 to 80% are mixed in a glass-lined pressure vessel. Whileagitating the mixture, the temperature is raised, under pressure toprevent boiling, to a point sufficient to melt all solids and ismaintained for a time period sufficient to ensure that the solids aremelted (usually about 30 minutes). After this heating period whilemaintaining the pressure, hot water (85°-100° C.) is added in an amountsufficient to give a final solids content of about 25-60%. The emulsionis then reheated to the previous temperature and held at a pressuresufficient to prevent boiling at this temperature for a period of timeto ensure homogeneity (usually about 10 minutes) followed by rapidcooling to ambient temperature (23° C.).

EXAMPLE 2

The following emulsion components were added to a pressure vessel: 32.3parts by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate, 10.8 parts by weight ofoxidized polyethylene emulsifiable wax, 0.5 parts of KOH as base, 6.4parts of surfactant (Tergitol 15-S-15) and sufficient water was added tobring the content of the mixture at this stage to about 70% solids. Theemulsion was then prepared according to the procedure in Example 1 withthe final water addition being sufficient to make the total watercontent equal to 50% by wt. of the mixture and the solids content of themixture to 32% by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate in the total mixture. Theresulting emulsion was applied to pellets of polypropylene having adensity of 0.902 and a melt flow rate of 9. The amount of emulsion usedwas calculated to achieve a solids level of 0.3-0.5% solids by weight onthe coated polypropylene pellets. The coated polypropylene pelletsbecame a light yellow-green in color following air drying.

EXAMPLE 3

The following emulsion components were added to a pressure vessel: 32.3parts by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate, 10.8 parts by wt. ofoxidized polyethylene emulsifiable wax, 0.5 parts of sodium tetraborateas base, 6.4 parts of surfactant (Tergitol 15-S-15) and sufficient waterwas added to bring the content of the mixture at this stage to about 70%solids. The emulsion was then prepared according to the procedure inExample 1 with the final water addition being sufficient to make thetotal water content equal to 50% by wt. of the mixture and the solidscontent of the mixture to 32% by wt. of octadecyl3-(3',5'-di-t-butyl-4hydroxyphenyl)propionate in the total mixture. Theresulting emulsion was applied to pellets of polypropylene having adensity of 0.902 and a melt flow rate of 9. The amount of emulsion usedwas calculated to achieve a solids level of 0.3-0.5% solids by weight onthe coated polypropylene pellets. The coated polypropylene pellets didnot exhibit a color shift from the original white color following airdrying.

EXAMPLE 4

The following emulsion components were added to a pressure vessel: 30%by wt. of an emulsifiable wax, 9% by wt. of surfactant (Tergitol15-S-15), 0.75% by wt. of KOH, 0.25% by wt. of sodium meta-bisulfite andsufficient water to bring the total solids content to 40%. Whileagitating the mixture under pressure to prevent boiling, the temperaturewas raised to a point sufficient to melt all solids and was maintainedfor thirty minutes to ensure that the solids were melted and was thenrapidly cooled to ambient temperature. 25% by wt. of the resultantemulsion was added to a one-gallon Ball-Mill, then 50% by wt. of1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl)-4-hydroxybenzyl)benzene,24.9% by wt. of additional water and 0.1% by wt. of an antifoaming agent(SWS 211) was added and the resultant mixture was ball milled for 16hours. The final solids content of1,3,5-trimethyl-2,4,6-tris(3,5-dit-butyl)-4-hydroxy-benzyl)benzene was50% by wt. of the total mixture. The resultant emulsion/dispersion wasapplied to pellets of polypropylene having a density of 0.902 and a meltflow rate of 9. The amount of emulsion/dispersion used was calculated toachieve a solids level of 0.3-0.5% solids by weight on the coatedpolypropylene pellets. The coated polypropylene pellets became a lightpurple-violet in color following air drying.

EXAMPLE 5

An emulsion/dispersion prepared according to Example 4 and substitutingsodium tetraborate for potassium hydroxide as base was applied topellets of polypropylene having a density of 0.902 and a melt flow rateof 9. The amount of emulsion/dispersion used was calculated to achieve asolids level of 0.3-0.5% solids by weight on the coated polypropylenepellets. The coated polypropylene pellets did not exhibit a color shiftfrom the original white color following air drying.

EXAMPLE 6 Comparative

The following components were added to a pressure vessel: 32.3 parts bywt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 10.8 parts byweight of oxidized polyethylene emulsifiable wax, 0.5 parts of KOH asbase, 6.4 parts of surfactant (Tergitol 15-S-15) and sufficient water tobring the content of the mixture at this stage to about 70% solids. Anattempt was made to prepare an emulsion according to the procedure inExample 1. The final water addition was sufficient to make the totalwater content equal to 50% by wt. of the mixture and the final solidscontent of the mixture to 32% by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane. The attempt toprepare the emulsion was unsuccessful due to the inability to coemulsifytetrakis[methylene-3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methanewith the oxidized polyethylene emulsifiable wax.

EXAMPLE 7

The following emulsion components were added to a pressure vessel: 11parts by wt. of tetrakis[methylene3-(3'-5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 21 parts by wt.of dilauryl thiodipropionate, 10.8 parts by weight of oxidizedpolyethylene emulsifiable wax, 0.5 parts of KOH as base, 6.4 parts ofsurfactant (Tergitol 15-S-15) and sufficient water to bring the contentof the mixture at this stage to about 70% solids. The emulsion was thenprepared according to the procedure in Example 1 with the final wateraddition being sufficient to make the total water content equal to 50%by wt. of the mixture and the solids content of the mixture to 32% bywt. of tetrakis[methylene3-(3'-5'-di-t-butyl4'-hydroxyphenyl)propionate]methane and dilaurylthiodipropionate. A stable emulsion resulted.

EXAMPLE 8

The following emulsion components were added to a pressure vessel: 7.3parts by wt. of tetrakis[methylene3-(3'-5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 21 parts by wt.of dilauryl thiodipropionate, 4 parts by wt. ofbis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, 10.8 parts byweight of oxidized polyethylene emulsifiable wax, 0.5 parts of KOH asbase, 6.4 parts of surfactant (Tergitol 15-S-15) and sufficient water tobring the content of the mixture at this stage to about 70% solids. Theemulsion was then prepared according to the procedure in Example 1 withthe final water addition being sufficient to make the total watercontent equal to 50% by wt. of the mixture and the solids content of themixture to 32% by wt. of tetrakis[methylene3-(3'-5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane and dilaurylthiodipropionate and bis(2,4-di-t-butylphenyl)pentaerythritoldiphosphite in the total mixture. A stable emulsion resulted.

EXAMPLE 9

The following emulsion components were added to a pressure vessel: 32.3parts by wt. of dilauryl thiodipropionate, 10.8 parts by weight ofoxidized polyethylene emulsifiable wax, 0.5 parts of KOH as base, 6.4parts of surfactant (Tergitol 15-S-15) and sufficient water to bring thecontent of the mixture at this stage to about 70% solids. The emulsionwas then prepared according to the procedure in Example 1 with the finalwater addition being sufficient to make the total water content equal to50% by wt. of the mixture and the final solids content of the mixture to32% by wt. of dilauryl thiodipropionate in the total mixture. A stableemulsion resulted.

EXAMPLE 10

The following emulsion components were added to a pressure vessel: 9.6parts by wt. of tetrakis[methylene3-(3'-5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 16 parts by wt.of dilauryl thiodipropionate, 6.4 parts by wt. oftris(monononylphenyl)phosphite, 10.8 parts by weight of oxidizedpolyethylene emulsifiable wax, 0.5 parts of KOH as base, 6.4 parts ofsurfactant (Tergitol 15-S-15) and sufficient water to bring the contentof the mixture at this stage to about 70% solids. The emulsion was thenprepared according to the procedure in Example 1 with the final wateraddition being sufficient to make the total water content equal to 50%by wt. of the mixture and the solids content of the mixture to 32% bywt. of tetrakis[methylene3-(3'-5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane and dilaurylthiodipropionate and tris(monononylphenyl)phosphite in the totalmixture. A stable emulsion resulted.

EXAMPLE 11

The following emulsion components were added to a pressure vessel: 8parts by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 10.7 parts bywt. of tris-(monononylphenyl)phosphite, 8 parts by wt. dilaurylthiodipropionate, 13.2 parts by weight of oxidized polyethyleneemulsifiable wax, 0.75 parts of KOH as base, and 6 parts of surfactant(Tergitol 15-S-15) and sufficient water to bring the solids content ofthe mixture at this stage to about 70% solids. The emulsion was thenprepared according to the procedure in Example 1 with the final wateraddition being sufficient to make the total water content equal to 60%by wt. of the mixture and the solids content of the mixture to 23% bywt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane,tris(monononylphenyl)phosphite, and dilauryl thiodipropionate in thetotal mixture. A stable emulsion resulted.

EXAMPLE 12

The following emulsion components were added to a pressure vessel: 9parts by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 12 parts by wt.of tris(monononylphenyl)phosphite, 9 parts by wt. dilaurylthiodipropionate, 10 parts by weight of oxidized polyethyleneemulsifiable wax, 0.75 parts of KOH as base, 6 parts of surfactant(Tergitol 15-S.15) and sufficient water to bring the solids content ofthe mixture at this stage to about 70% solids. The emulsion was thenprepared according to the procedure in Example 1 with the final wateraddition being sufficient to make the total water content equal to 60%by wt. of the mixture and the solids content of the mixture to 26% bywt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane,tris(monononylphenyl)phosphite, and dilauryl thiodipropionate in thetotal mixture. A stable emulsion resulted.

EXAMPLE 13

The following emulsion components were added to a pressure vessel: 9.6parts by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 12.8 parts bywt. of tris(monononylphenyl)phosphite, 9.6 parts by wt. dilaurylthiodipropionate, 8 parts by weight of oxidized polyethyleneemulsifiable wax, 0.75 parts of KOH as base, and 6 parts of surfactant(Tergitol 15-S.15) and sufficient water to bring the solids content ofthe mixture at this stage to about 70% solids. The emulsion was thenprepared according to the procedure in Example 1 with the final wateraddition being sufficient to make the total water content equal to 60%by wt. of the mixture and the solids content of the mixture to 27% bywt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane,tris(monononylphenyl)phosphite, and dilauryl thiodipropionate in thetotal mixture. A stable emulsion resulted.

EXAMPLE 14

The following emulsion components were added to a pressure vessel: 10.3parts by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 15.4 parts bywt. of tris(monononylphenyl)phosphite, 10.3 parts by wt. dilaurylthiodipropionate, 4 parts by weight of oxidized polyethyleneemulsifiable wax, 0.75 parts of KOH as base, 6 parts of surfactant(Tergitol 15-S-15) and sufficient water to bring the solids content ofthe mixture at this stage to about 70% solids. The emulsion was thenprepared according to the procedure in Example 1 with the final wateraddition being sufficient to make the total water content equal to 60%by wt. of the mixture and the solids content of the mixture to 31% bywt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane,tris(monononylphenyl)phosphite, and dilauryl thiodipropionate in thetotal mixture. A stable emulsion resulted.

EXAMPLE 15 Comparative

The following emulsion components were added to a pressure vessel: 8parts by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4,-hydroxyphenyl)propionate]methane, 18.8 parts bywt. dilauryl thiodipropionate, 13.2 parts by weight of oxidizedpolyethylene emulsifiable wax, 1.5 parts of KOH as base, and 6 parts ofsurfactant (Tergitol 15-S-15) and sufficient water to bring the solidscontent of the mixture at this stage to about 70% solids. The emulsionwas then prepared according to the procedure in Example 1 with the finalwater addition being sufficient total water content equal to 69% by wt.of the mixture and the solids content of the mixture 17% by wt. oftetrakis[methylene3-(3',5'-di-t-butyl-4'hydroxyphenyl)propionate]methane and dilaurylthiodipropionate in the total mixture. A poor quality emulsion resulted.

EXAMPLE 16

The following emulsion components were added to a pressure vessel: 8parts by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 18.8 parts bywt. dilauryl thiodipropionate, 13.2 parts by weight of oxidizedpolyethylene emulsifiable wax, 0.75 parts of KOH as base, 6 parts ofsurfactant (Tergitol 15-S-15) and sufficient water to bring the solidscontent of the mixture at this stage to about 70% solids. The emulsionwas then prepared according to the procedure in Example 1 with the finalwater addition being sufficient to make the total water content equal to69% by wt. of the mixture and the solids content of the mixture 17% bywt. of tetrakis[methylene3-(3',5'di-t-butyl-4'-hydroxyphenyl)propionate]methane and dilaurylthiodipropionate in the total mixture. A stable emulsion resulted.

EXAMPLE 17 Comparative

The following emulsion components were added to a pressure vessel: 30parts by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate, 10 parts by weight ofoxidized polyethylene emulsifiable wax, 0.2 parts of sodium tetraborateas base, 6 parts of surfactant (Tergitol 15-S.15) and sufficient waterto bring the solids content of the mixture at this stage to about 70%solids. The emulsion was then prepared according to the procedure inExample 1 with the final water addition being sufficient to make thetotal water content equal to 50% by wt. of the mixture and the solidscontent of the mixture to 32.5% by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate in the total mixture. Apoor quality emulsion resulted.

EXAMPLE 18

The following emulsion components were added to a pressure vessel: 30parts by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate, 10 parts by weight ofoxidized polyethylene emulsifiable wax, 0.4 parts of sodium tetraborateas base, 6 parts of surfactant (Tergitol 15-S-15) and sufficient waterto bring the solids content of the mixture at this stage to about 70%solids. An aqueous emulsion was then prepared according to the procedurein Example 1 with the final water addition being sufficient to make thetotal water content equal to 50% by wt. of the mixture, and the solidscontent of the mixture 32.5% by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate in the total mixture. Astable emulsion resulted.

EXAMPLE 19

The following emulsion components were added to a pressure vessel: 30parts by wt. of octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl)propionate, 10 parts by weight ofoxidized polyethylene emulsifiable wax, 0.8 parts of sodium tetraborateas base, 6 parts of surfactant (Tergitol 15-S-15) and sufficient waterto bring the solids content of the mixture at this stage to about 70%solids. The emulsion was then prepared according to the procedure inExample 1 with the final water addition being sufficient to make thetotal water content equal to 50% by wt. of the mixture and the solidscontent of the mixture to 32.5% by wt. of octadecyl3-(3',5'-dit-butyl-4-hydroxyphenyl)propionate in the total mixture. Astable emulsion resulted.

EXAMPLE 20 Comparative

Polypropylene pellets having a density of 0.906 and a melt flow rate of4 were melt compounded with sufficient tetrakis[methylene3-(3',5'-di-t-butyl4'-hydroxyphenyl)propionate]methane,tris(monononylphenyl)phosphite, and dilauryl thiodipropionate to providea stabilization level of 0.15%, 0.10%, and 0.25% by wt. respectively tothe polypropylene. Following extrusion and pelletization, the stabilizedpolypropylene was oven aged at 150° C. to check oxidative stability. Thepolypropylene had not exhibited evidence of degradation after 49 days at150° C.

EXAMPLE 21

The following emulsion components were added to a pressure vessel: 8parts by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, 13.4 parts bywt. of dilauryl thiodipropionate, 5.4 parts by wt. oftris(monononylphenyl)phosphite, 13.2 parts by wt. of oxidizedpolyethylene emulsifiable wax, 0.75 parts by wt. of KOH as base, 6 partsby wt. of surfactant (Tergitol 15-S-15) and sufficient water to bringthe solids content of the mixture at this stage to about 70% solids. Theemulsion was then prepared according to the procedure in Example 1 withthe final water addition being sufficient to make the total watercontent equal to 50% by wt. of the mixture and the solids content of themixture to about 17% by wt. of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, dilaurylthiodipropionate, and tris(monononylphenyl)phosphite. A stable emulsionresulted.

EXAMPLE 22

The emulsion of Example 21 was applied to polypropylene pellets having adensity of 0.906 and a melt flow rate of 4 in a manner calculated tocoat the polypropylene with 0.15%, 0.25%, and 0.10% by wt.,respectively, of tetrakis[methylene3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, dilaurylthiodipropionate, and tris(monononylphenyl)phosphite. The coatedpolypropylene was oven aged at 150° C. to check oxidative stability. Thepolypropylene had not exhibited evidence of degradation after 49 days at150° C. indicating that polypropylene stabilized with an aqueousemulsion of tetrakis[methylene3-(3',5'di-t-butyl-4'-hydroxyphenyl)propionate]methane, dilaurylthiodipropionate, and tris(monononylphenyl)phosphite compares favorablywith polypropylene stabilized with the same compounds at the same levelas in Example 20.

EXAMPLE 23

An emulsion was prepared according to the procedure in Example 1 andusing the ingredients in Example 4, and 25% by wt. of the emulsion wasadded to a 1-gallon Ball-Mill. Then 38.4% by wt. octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl) propionate, 24.2% by wt. 48%aqueous calcium stearate, 12% by wt. additional water, 0.2% by wt. of anantifoaming agent (SWS 211), and 0.1% by wt. each of methyl and propylparaben (biocides) was added and the resultant mixture was ball milledfor 16 hours. The final solids content of octadecyl3-(3',5'-di-t-butyl-4hydroxyphenyl) propionate and calcium stearate wasat a 10:3 wt. ratio (38.4:11.6 wt. %). The resultant emulsion/dispersionwas applied to polypropylene pellets having a density of 0.902 and amelt flow rate of 9. The amount of emulsion/dispersion used wascalculated to achieve a solids level of 0.1% solids by wt. on the coatedpolypropylene pellets. The coated polypropylene did not exhibit a colorshift when dryed in an oven for 3 days at a temperature of 150° C.

EXAMPLE 24

An emulsion was prepared according to the procedure in Example 1 andusing the ingredients in Example 4, and 26.3% by wt. of the emulsion wasadded to a 1-gallon Ball-Mill. Then 40% by wt. octadecyl3-(3',5'-di-t-butyl-4-hydroxyphenyl) propionate, 26.3% by wt. 48%aqueous calcium stearate, 1.5% by wt. of surfactant (Igepal CO 630),0.5% by wt. of surfactant (Igepal CO 210), 0.2% by wt. of an antifoamingagent (SWS 211), and 0.1% by wt. each of methyl and propyl paraben(biocides) was added and the resultant mixture was ball milled for 16hours. The final solids content of octadecyl3-(3',5'-dit-butyl-4-hydroxyphenyl) propionate and calcium stearate wasat a 8:3 wt. ratio (40:12.6 wt. %). The resultant emulsion/dispersionwas applied to polypropylene pellets having a density of 0.902 and amelt flow rate of 9. The amount of emulsion/dispersion used wascalculated to achieve a solids level of 0.08% by wt. on the coatedpolypropylene pellets. The coated polypropylene pellets die not exhibita color shift when dryed in an oven for 3 days at a temperature of 150°C.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

We claim:
 1. Method of preparing aqueous emulsions which include anemulsifiable wax and at least one processing, stabilizing or otherfunctional polymer additive component, said method comprising(1)agitating a mixture which contains by weight, about 20 to about 80percent water, about 5 to about 35 percent of an emulsifiable wax, about0.2 to about 1.0 percent of a base, and about 2 to about 30 percent of asurfactant; at a temperature sufficient to melt all solids; and under apressure sufficient to prevent boiling for a period of time to ensurehomogeneity; (2) cooling said emulsion to ambient temperature; and (3)milling in the range of 20 up to 70 wt. % of the cooled emulsion with inthe range of about 30 up to 80 wt. % of said additive(s) optionally with0-35 wt. % water, and optionally with 0-1 wt. % antifoam for a period oftime to ensure substantial homogeneity.
 2. Method of claim 1 whereinsaid base has a pH in the range of greater than 7 to equal to or lessthan about
 12. 3. Method of claim 2 wherein said base is selected fromsodium tetraborate, sodium carbonate, sodium bicarbonate, calciumcarbonate or magnesium carbonate.
 4. Method of claim 2 wherein saidadditive component is selected from:antioxidants, coupling agents,antistatic agents, nucleating agents, metal deactivators,lubricants-slip/antiblocking agents, UV inhibitors, or flameretardants,as well as mixtures of any two or more thereof.